Our laurel hedge which is approximately 4 years old has continually developed browning tips and yellowing of leaves which then fall off. There is always plenty of new growth but new leaves then follow suit. The hedge is planted in clay soil and not sure what soil preparation was initially carried out. We have tried growmore, seaweed feed, more watering. However, it is a fairly damp corner and wonder if the problem is actually waterlogging of roots? Can anyone help??